#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<string>
using namespace std;

int main(int argc, char* argv[])
{
	string a = "hello world";
	string b = a;
	if (a.c_str() == b.c_str())
	{
		cout << "true" << endl;
	}
	else cout << "false" << endl;
	string c = b;
	c = "";
	if (a.c_str() == b.c_str())
	{
		cout << "true" << endl;
	}
	else cout << "false" << endl;
	a = "";
	if (a.c_str() == b.c_str())
	{
		cout << "true" << endl;
	}
	else cout << "false" << endl;
	return 0;
}